Process for fabricating an offensive and defensive projectile head, and projectile head produced according to this process

ABSTRACT

Process for fabricating an offensive and defensive projectile head for antipersonnel use comprising a hollow metallic body and provided with reducing slits, consisting of stamping out a metallic blank of definite quality, thickness and form; of striking, impressing or marking, by pressing or rolling, one or both faces of this blank with a set of impressions determining the reducing slits; and in swaging the said blank to give it the desired form.

United States Patent I I I 1 Inventor Louis Dessart. 27. rue de Cheratte.

Vivegnis Lei-Liege. Belgium Appl. No. 714,586

Filed Mar. 20, 1968 Patented July 6, 1971 I Priority Mar. 31, 1967 I Belgium 696.464

PROCESS FOR FABRICATING AN OFFENSIVE AND DEFENSIVE PROJECTILE HEAD, AND PROJECTILE HEAD PRODUCED ACCORDING TO THIS PROCESS 3 Claims, 8 Drawing Figs.

US. Cl 29/ 1.21

lnt.Cl.... B2lk 21/06 Field of Search 29/1 .21; 72/379 Primary ExaminerH. A. Kilby, .lr. AttarneyJacob L. Kollin ABSTRACT: Process for fabricating an offensive and defensive projectile head for antipersonnel use comprising a hollow metallic body and provided with reducing slits, consisting of stamping out a metallic blank of definite quality, thickness and form; of striking, impressing or marking, by pressing or rolling, one or both faces of this blank with a set of impressions determining the reducing slits; and in swaging the said blank to give it the desired form.

\III

vPATENTED JUL e um III! II I I II INVENTOR Zoe/l: Dessart ATTORNEY PROCESS FOR FABRICATING AN OFFENSIVE AND DEFENSIVE PROJECTILE HEAD, AND PROJECTILE HEAD PRODUCED ACCORDING TO THIS PROCESS It is known that various kinds of reductions on the surface of the body of projectiles for antipersonnel use have already been devised and carried into effect with the object of encouraging splinter formation.

Previously, hollow metallic bodies have been constructed in which reduction grooves were provided in the interior; these, intended to receive a quantity of explosive, encourage and systematize fragmentation.

Experiments have proved that such an arrangement allows of providing for the form, the quantity, and even the direction of the fragments, and that for a given projectile shape; but this arrangement of the grooves demands the use of special and expensive material and machines; in a word, enormously increases the difficulties of achieving fabrication.

The present invention has the object of simplifying the method of production of these slits and of being able to carry them out by means of standard machines, such as presses.

The invention thus has as an object a process for fabricating an explosive head for antipersonnel use, comprising a hollow metallic body and provided with reducing slits, which is characterized in that it consists in stamping out a metallic blank of definite quality, thickness and shape, of striking, impressing or marking in the press or by rolling, one or both faces of this blank with a set of impressions determining the reducing slits and in swaging the said blank to give it the desired form.

The process according to the invention further consists in producing a projectile head by the superposition of two of these hollow bodies, the free edges of which are joined by soldering.

The invention has likewise as an object all projectile heads produced according to the said process.

Other characteristics of the invention will also be obvious from the description whichv follows, based on the annexed drawing, by way of unique (but not limiting) example, of the production of a head for antipersonnel use showing internal fragmentation. In it are:

FIG. 1 a plan view of a stamped out blank;

FIG. 2 a plan view of the blank of FIG. I after marking the impression of a single face;

FIG. 3 a section of the blank of FIG. 2 swaged in the form a hemisphere;

FIG. 4 a section in a blank after marking an impression with swaging in the form of a hemisphere comprising an orifice of determined form, for example for mounting the fuse;

FIG. 5 a section identical with that in FIG. 4 but with the orifice directed towards the interior;

FIG. 6 a view in elevation, partially cutaway, of the projectile head formed by the union of the two hemispheres of FIGS. 3 and 4;

FIG. 7 a section of a blank showing the form of the grooves struck with concentric grooves 2, then impressed, using a press of known construction by grooves 3 passing through radii, these radial lines 3 being very rarely in line between each concentric groove 2. These radii nearly always then become small slits 4 (FIG. 2). The grooved disc is then swaged by a swaging tool of known construction to present the form of a hemisphere 1 (FIG. 3). A second metallic disc is stamped out by a press of known construction and grooved like that in FIGS. I and 2 and then swaged by a swaging tool to present an hemispherical form 1' comprising an orifice 5 obtained by pressing with a pressing tool of known construction and directed towards the outside (FIG. 4). Instead of this hemisphere 1', one can obtain a hemisphere 1"(FIG. 5) comprising an orifice 6 obtained by pressing with a press of known construction and turned back inwardly. The two hemispheres I and 1 or 1 and l", arejoined by soldering (FIG. 6), the explosive not being shown in the drawing, to constitute the head of the projectile.

It is essential that the form and the depth of the grooves or slits produced are designed in such a way that the swaging finally regularizes their outline so that they can, after loading, contain the same quantity of explosive. On loading, the explosive enters the grooves produced and faithfully assumes their pattern and their outline. The width of the grooves or slits, their depth, the construction angle and the width of the apex of that angle can vary from one realization to the other, but should be carefully calculated, because a correction'comes into operation on swaging. In this connection may be seen, in FIGS. 7 and 8, the outlines of the grooves a, b before swaging and a, b after swaging, the opposite being produced when exterior slits are made likewise.

During explosion, separation takes place according to the prefragmentation design, stresses taking place not only in the bottom but also laterally in the profile of the grooves and tending to separate the segments one from another. There is thus realized a desired prefragmentation which allows of providing for the weight and the number of the splinters with regularity and precision.

In the realization described above and represented in the drawing, the head of the projectile comprises only internal fragmentation, but, of course, it would not be going outside the scope of the invention to produce, according to the same process, a projectile head with fragmentation on both faces. The circular or radial slits, produced on one part and another of the faces of the blank (FIG. 1), would in this case be situated exactly opposite to one another, producing at their summit the desired break-initiators. In the same way, the head represented is a sphere; but it can take any form whatever, oval or otherwise.

lclaim:

I. A process for fabrication of an offensive and defensive projectile head for antipersonnel use comprising a hollow metallic body provided with reduced grooves, consisting of stamping out a planar metallic blank of definite quality, thickness and form; of impressing one or both faces of this blank with a set of concentric annular grooves, and a set of short nonaligned radial grooves extending between each concentric groove to determine the reduced grooves; and swaging the said blank to give it hemispherical form.

2. The process of fabrication according to claim 1 further consisting of pressing an orifice in the hollow body.

3. The process of fabrication according to claim 2 further consisting of superposing two hollow bodies, one of which is provided with an orifice and of uniting their free edges by soldering. 

1. A process for fabrication of an offensive and defensive projectile head for antipersonnel use comprising a hollow metallic body provided with reduced grooves, consisting of stamping out a planar metallic blank of definite quality, thickness and form; of impressing one or both faces of this blank with a set of concentric annular grooves, and a set of short nonaligned radial grooves extending between each concentric groove to determine the reduced grooves; and swaging the said blank to give it hemispherical form.
 2. The process of fabrication according to claim 1 further consisting of pressing an orifice in the hollow body.
 3. The process of fabrication according to claim 2 further consisting of superposing two hollow bodies, one of which is provideD with an orifice and of uniting their free edges by soldering. 